Solid-state imaging apparatus and electronic apparatus

ABSTRACT

A solid-state imaging apparatus includes a pixel array part having a plurality of pixels are two-dimensionally arranged, in which each pixel has a first photoelectric conversion region formed above a semiconductor layer, a second photoelectric conversion region formed in the semiconductor layer, a first filter configured to transmit a light in a predetermined wavelength region corresponding to a color component, and a second filter having different transmission characteristics from the first filter, one photoelectric conversion region out of the first photoelectric conversion region and the second photoelectric conversion region photoelectrically converts a light in a visible light region, the other photoelectric conversion region photoelectrically converts a light in an infrared region, the first filter is formed above the first photoelectric conversion region, and the second filter has transmission characteristics of making wavelengths of light in an infrared region absorbed in the other photoelectric conversion region formed below the first filter the same.

TECHNICAL FIELD

The present technology relates to a solid-state imaging apparatus and anelectronic apparatus, and particularly to a solid-state imagingapparatus capable of generating a high-resolution IR image while keepinghigh quality of a visible light image, and an electronic apparatus.

BACKGROUND ART

An image sensor shoots an image obtained by visible lights (denoted asvisible light image below) by use of R (read), G (green), and B (blue)color filters. Further, an image sensor shoots an image obtained byinfrared rays (IR) (denoted as IR image below) by detecting from avisible light to an infrared ray without the use of color filters inorder to improve a night-vision sensitivity and to acquire objectinformation which cannot be shot by a visible light in addition to avisible light image.

On the other hand, not acquiring either a visible light image or an IRimage at one time, a demand to acquire both a visible light image and anIR image at the same time has increased. For example, there is known, asa pixel layout pattern, a configuration in which IR pixels correspondingto the IR component are two-dimensionally arranged in addition to Rpixels corresponding to the R component, G pixels corresponding to the Gcomponent, and B pixels corresponding to the B component thereby toacquire a visible light image and an IR image at the same time.

Further, there is disclosed a configuration in which an infraredphotoelectric conversion layer configured to absorb a light in aninfrared region is formed above a semiconductor substrate in whichphotodiodes configured to detect lights of R component, G component, andB component are formed thereby to acquire a visible light image and anIR image at the same time (see Patent Document 1, for example).

CITATION LIST Patent Document

-   Patent Document 1: Japanese Patent Application Laid-Open No.    2009-27063

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

In the pixel structure disclosed in Patent Document 1, the infraredphotoelectric conversion layer configured to absorb a light in aninfrared region is provided for all the pixels, and an IR image using IRsignals obtained from all the IR pixels can be acquired.

On the other hand, in the pixel structure disclosed in Patent Document1, an inorganic filter (filter including an inorganic material) formedbelow the infrared photoelectric conversion layer disperses the colorcomponents without providing color filters configured to disperse thecolor components of lights detected by the photodiodes above theinfrared photoelectric conversion layer.

Here, the spectroscopic shape of a light obtained by the inorganicfilter is inferior to the spectroscopic shape of a light obtained by thecolor filters, and thus the quality of a visible light image using RGBsignals obtained from R pixels, G pixels, and B pixels is lower in usingthe inorganic filter than in using the color filters. Therefore, atechnology for generating a high-resolution IR image while keeping highquality of a visible light image has been required.

The present technology has been made in terms of such situations, and isdirected to generating a high-resolution IR image while keeping highquality of a visible light image.

Solutions to Problems

A solid-state imaging apparatus according to an aspect of the presenttechnology is a solid-state imaging apparatus including: a pixel arraypart in which pixels each having a first photoelectric conversion regionformed above a semiconductor layer and a second photoelectric conversionregion formed in the semiconductor layer are two-dimensionally arranged,in which each of the pixels further has: a first filter configured totransmit a light in a predetermined wavelength region corresponding to acolor component; and a second filter having different transmissioncharacteristics from the first filter, one photoelectric conversionregion out of the first photoelectric conversion region and the secondphotoelectric conversion region photoelectrically converts a light in avisible light region and the other photoelectric conversion regionphotoelectrically converts a light in an infrared region, the firstfilter is formed above the first photoelectric conversion region, andthe second filter has transmission characteristics of making wavelengthsof lights in an infrared region absorbed in the other photoelectricconversion region formed below the first filter the same.

In a solid-state imaging apparatus according to one aspect of thepresent technology, each of pixels two-dimensionally arranged in a pixelarray part has a first photoelectric conversion region formed above asemiconductor layer, a second photoelectric conversion region formed inthe semiconductor layer, a first filter configured to transmit a lightin a predetermined wavelength region corresponding to a color component,and a second filter having different transmission characteristics fromthe first filter. Then, one photoelectric conversion region out of thefirst photoelectric conversion region and the second photoelectricconversion region photoelectrically converts a light in a visible lightregion, and the other photoelectric conversion region photoelectricallyconverts a light in an infrared region. Further, the second filteruniforms wavelengths of lights in an infrared region absorbed in theother photoelectric conversion region formed below the first filter.

An electronic apparatus according to an aspect of the present technologyis an electronic apparatus mounting a solid-state imaging apparatusthereon, the solid-state imaging apparatus including: a pixel array partin which pixels each having a first photoelectric conversion regionformed above a semiconductor layer and a second photoelectric conversionregion formed in the semiconductor layer are two-dimensionally arranged,in which each of the pixels further has: a first filter configured totransmit a light in a predetermined wavelength region corresponding to acolor component; and a second filter having different transmissioncharacteristics from the first filter, one photoelectric conversionregion out of the first photoelectric conversion region and the secondphotoelectric conversion region photoelectrically converts a light in avisible light region, and the other photoelectric conversion regionphotoelectrically converts a light in an infrared region, the firstfilter is formed above the first photoelectric conversion region, andthe second filter has characteristics of making wavelengths of lights inan infrared region absorbed in the other photoelectric conversion regionformed below the first filter the same.

In an electronic apparatus according to one aspect of the presenttechnology, each of pixels two-dimensionally arranged in a pixel arraypart in a solid-state imaging apparatus mounted thereon has a firstphotoelectric conversion region formed above a semiconductor layer, asecond photoelectric conversion region formed in the semiconductorlayer, a first filter configured to transmit a light in a predeterminedwavelength region corresponding to a color component, and a secondfilter having different transmission characteristics from the firstfilter. Then, one photoelectric conversion region out of the firstphotoelectric conversion region and the second photoelectric conversionregion photoelectrically converts a light in a visible light region, andthe other photoelectric conversion region photoelectrically converts alight in an infrared region. Further, the second filter uniformswavelengths of lights in an infrared region absorbed in the otherphotoelectric conversion region formed below the first filter.

Additionally, each of the solid-state imaging apparatus and theelectronic apparatus according to one aspect of the present technologymay be an independent apparatus, or may be an internal block configuringone apparatus.

Effects of the Invention

According to one aspect of the present technology, it is possible togenerate a high-resolution IR image while keeping high quality of avisible light image.

Additionally, the effects described herein are not necessarilyrestrictive, and any effect described in the present disclosure may beobtained.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating one embodiment of a solid-state imagingapparatus according to the present technology.

FIG. 2 is a cross-section view illustrating a structure of pixels.

FIG. 3 is a diagram illustrating transmissivity of color filters in eachwavelength band.

FIG. 4 is a diagram illustrating an absorption rate of an organicphotoelectric conversion layer in each wavelength band.

FIG. 5 is a diagram illustrating absorption rates of an R pixel, a Gpixel, and a B pixel in each wavelength band.

FIG. 6 is a diagram illustrating transmissivity of an R filter, a Gfilter, and a B filter in each wavelength band.

FIG. 7 is a diagram for explaining that a light spectrum detected per IRpixel is different.

FIG. 8 is a cross-section view illustrating a structure of pixelsaccording to a first embodiment.

FIG. 9 is a diagram illustrating transmissivity of a dual-bandpassfilter in each wavelength band.

FIG. 10 is a diagram illustrating characteristics of each pixel beforethe dual-bandpass filter is inserted.

FIG. 11 is a diagram illustrating characteristics of each pixel afterthe dual-bandpass filter is inserted.

FIG. 12 is a diagram for explaining that a light spectrum detected perIR pixel is the same.

FIG. 13 is a cross-section view of a structure of pixels according to asecond embodiment.

FIG. 14 is a diagram illustrating a structure of a multilayered filter.

FIG. 15 is a diagram illustrating transmissivity of the multilayeredfilter in each wavelength band.

FIG. 16 is a diagram illustrating characteristics of each pixel beforethe multilayered filter is inserted.

FIG. 17 is a diagram illustrating characteristics of each pixel afterthe multilayered filter is inserted.

FIG. 18 is a cross-section view illustrating a structure of pixelsaccording to a third embodiment.

FIG. 19 is a diagram illustrating a structure of a plasmon filter.

FIG. 20 is a cross-section view illustrating a structure of pixelsaccording to a fourth embodiment.

FIG. 21 is a diagram illustrating transmissivity of a dual-bandpassfilter in each wavelength band.

FIG. 22 is a diagram illustrating characteristics of each pixel beforethe dual-bandpass filter is inserted.

FIG. 23 is a diagram illustrating characteristics of each pixel afterthe dual-bandpass filter is inserted.

FIG. 24 is a cross-section view illustrating a structure of pixelsaccording to a fifth embodiment.

FIG. 25 is a diagram illustrating transmissivity of a multilayeredfilter in each wavelength band.

FIG. 26 is a diagram illustrating a readout circuit for an organicphotoelectric conversion layer.

FIG. 27 is a diagram illustrating a readout circuit for a photodiode.

FIG. 28 is a cross-section view illustrating other structure of thepixels according to the first embodiment.

FIG. 29 is a cross-section view illustrating other structure of thepixels according to the second embodiment.

FIG. 30 is a cross-section view illustrating other structure of thepixels according to the third embodiment.

FIG. 31 is a cross-section view illustrating other structure of thepixels according to the fourth embodiment.

FIG. 32 is a cross-section view illustrating other structure of thepixels according to the fifth embodiment.

FIG. 33 is a diagram illustrating an exemplary configuration of anelectronic apparatus having a solid-state imaging apparatus.

FIG. 34 is a diagram illustrating exemplary use of the solid-stateimaging apparatus.

MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present technology will be described below withreference to the drawings. Additionally, the description will be made inthe following order.

1. Configuration of solid-state imaging apparatus

2. First embodiment: structure using dual-bandpass filter (OPC: RGBpixels, PD: IR pixels)

3. Second embodiment: structure using multilayered filter (OPC: RGBpixels, PD: IR pixels)

4. Third embodiment: structure using plasmon filter (OPC: RGB pixels,PD: IR pixels)

5. Fourth embodiment: structure using dual-bandpass filter (OPC: IRpixels, PD: RGB pixels)

6. Fifth embodiment: structure using multilayered filter (OPC: IRpixels, PD: RGB pixels)

7. Readout circuit

8. Variant

9. Configuration of electronic apparatus

10. Exemplary use of solid-state imaging apparatus

<1. Configuration of Solid-State Imaging Apparatus>

(Exemplary Configuration of Solid-State Imaging Apparatus)

FIG. 1 is a diagram illustrating one embodiment of a solid-state imagingapparatus according to the present technology.

A CMOS image sensor 10 of FIG. 1 is a solid-state imaging apparatususing complementary metal oxide semiconductor (CMOS). The CMOS imagesensor 10 takes in an incident light (image light) from an object via anoptical lens system (not illustrated), converts the amount of theincident light formed on the imaging surface into electric signals inunits of pixel, and outputs the electric signals as pixel signals.

In FIG. 1, the CMOS image sensor 10 is configured of a pixel array part11, a vertical drive circuit 12, column signal processing circuits 13, ahorizontal drive circuit 14, an output circuit 15, a control circuit 16,and an I/O terminal 17.

A plurality of pixels 100 are two-dimensionally arranged in the pixelarray part 11. A pixel 100 is configured of an organic photoelectricconversion layer (OPC) as a photoelectric conversion region and aphotodiode (PD) as well as a plurality of pixel transistors.

The vertical drive circuit 12 is configured of a shift register, forexample, selects a predetermined pixel drive line 21, supplies theselected pixel drive line 21 with a pulse for driving the pixels 100,and drives the pixels 100 in units of row. That is, the vertical drivecircuit 12 selects and scans the respective pixels 100 in the pixelarray part 11 in units of row sequentially in the vertical direction,and supplies the pixel signals based on signal charges (charges)generated depending on the amount of received light in the organicphotoelectric conversion layer or the photodiodes in the respectivepixels 100 to the column signal processing circuits 13 via verticalsignal lines 22.

The column signal processing circuits 13 are arranged in units of columnof the pixels 100, and perform a signal processing such as noisecancellation on the signals output from one row of pixels 100 per columnof pixels. For example, the column signal processing circuits 13 performa signal processing such as correlated double sampling (CDS) forcanceling a pixel-specific fixed pattern noise and analog/digital (A/D)conversion.

The horizontal drive circuit 14 is configured of a shift register, forexample, sequentially outputs a horizontal scanning pulse, selects eachof the column signal processing circuits 13 in turn, and causes pixelsignals to be output from each of the column signal processing circuits13 to a horizontal signal line 23.

The output circuit 15 performs a signal processing on and outputs thesignals sequentially supplied from each of the column signal processingcircuits 13 via the horizontal signal line 23. Additionally, the outputcircuit 15 may perform only buffering, for example, or may perform blacklevel adjustment, column variation correction, various digital signalprocessings, and the like.

The control circuit 16 controls the operations of each part in the CMOSimage sensor 10. For example, the control circuit 16 receives an inputclock signal and data for giving an instruction on an operation mode orthe like, and outputs data such as internal information of the CMOSimage sensor 10. That is, the control circuit 16 generates clock signalsor control signals as the references of the operations of the verticaldrive circuit 12, the column signal processing circuits 13, thehorizontal drive circuit 14, and the like on the basis of a verticalsynchronization signal, a horizontal synchronization signal, and amaster clock signal. The control circuit 16 outputs the generated clocksignals or control signals to the vertical drive circuit 12, the columnsignal processing circuits 13, the horizontal drive circuit 14, and thelike.

The I/O terminal 17 exchanges signals with the outside.

The thus-configured CMOS image sensor 10 of FIG. 1 is assumed as a CMOSimage sensor in a column AD system in which the column signal processingcircuits 13 configured to perform the CDS processing and the A/Dconversion processing are arranged per column of pixels. Further, theCMOS image sensor 10 of FIG. 1 may be assumed as a CMOS image sensor ofbackside irradiation type or surface irradiation type. Additionally, theconfiguration illustrated in FIG. 1 is exemplary, and may be differentdepending on a configuration of a readout circuit (for the organicphotoelectric conversion layer and the photodiode) of a pixel 100, forexample. For example, in a case where the readout circuit for theorganic photoelectric conversion layer employs a system in which amemory part, for reducing noises is provided, not the above CDSprocessing but an external memory part is used to cancel noises.

Incidentally, the structure of the pixels 100 two-dimensionally arrangedin the pixel array part 11 in the CMOS image sensor 10 may employ thestructures of pixels according to a first embodiment to a fifthembodiment described below. The structures of pixels according to thefirst embodiment to the fifth embodiment arranged in the pixel arraypart 11 will be described below.

Additionally, the pixels according to the first embodiment are denotedas pixels 100 and are discriminated from the pixels according to theother embodiments in the following description for convenientdescription. Similarly, the pixels according to the second embodiment tothe fifth embodiment are denoted as pixels 200, pixel 300, pixels 400,and pixels 500, respectively, but the pixels are also two-dimensionallyarranged in the pixel array part 11 in the CMOS image sensor 10 (FIG.1).

<2. First Embodiment: Structure Using Dual-Bandpass Filter (OPC: RGBPixels, PD: IR Pixels)>

A structure of the pixels 100 according to the first embodiment will befirst described with reference to FIG. 2

to FIG. 12.

(Structure of Pixels)

FIG. 2 is a cross-section view illustrating a structure of the pixels100. FIG. 2 illustrates three pixels 100-1 to 100-3 arranged atarbitrary positions among a plurality of pixels 100 two-dimensionallyarranged in the pixel array part 11 by way of example. However, thepixels 100-1 to 100-3 employ a structure of backside irradiation type.

Photodiodes 115-1 to 115-3 and charge holding parts 124-1 to 124-3 areformed in a semiconductor layer 114 including silicon (Si) or the likein the pixels 100-1 to 100-3, respectively. A wiring layer 116 isassumed below the semiconductor layer 114, where a plurality of wirings131 are formed. Further, an interlayer insulative film 113 and anorganic photoelectric conversion layer 112 are laminated on thesemiconductor layer 114.

The organic photoelectric conversion layer 112 absorbs only lights inthe visible light region, and generates signal charges (charge)corresponding to lights of the respective color components of R (red)component, G (green) component, and B (blue) component. A transparentelectrode 121 configured to read out a signal charge generated in theorganic photoelectric conversion layer 112, and transparent electrodes122-1 to 122-3 are formed on the top and back of the organicphotoelectric conversion layer 112, respectively.

Additionally, the transparent electrode 121 is formed on the entiresurface of the organic photoelectric conversion layer 112. Further, thetransparent electrodes 122-1 to 122-3 are formed depending on a pixelpitch. The transparent electrode 122-1 is connected to the chargeholding part 124-1 via an electrode 12 3-1. Similarly, the transparentelectrodes 122-2 and 122-3 are connected to the charge holding parts124-2 and 124-3 via electrodes 123-2 and 123-3, respectively.

An R color filter 111-1 configured to transmit an R-component light isformed on the side in which a light is incident of the pixel 100-1 amongthe pixels 100-1 to 100-3. Similarly, a G color filter 111-2 configuredto transmit a G-component light is formed on the side in which a lightis incident of the pixel 100-2. Further, a B color filter 111-3configured to transmit a B-component light is formed on the side inwhich a light is incident of the pixel 100-3.

That is, in the pixel 100-1, an R-component light in the visible lightregion among the lights transmitting through the R color filter 111-1 isabsorbed in the organic photoelectric conversion layer 112 while anIR-component light in the infrared region transmits through the organicphotoelectric conversion layer 112. Thus, a signal charge correspondingto the R-component light is generated in the organic photoelectricconversion layer 112 in the pixel 100-1. On the other hand, a signalcharge corresponding to the IR-component light is generated in thephotodiode 115-1.

Further, in the pixel 100-2, a G-component light in the visible lightregion among the lights transmitting through the G color filter 111-2 isabsorbed in the organic photoelectric conversion layer 112 while anIR-component light in the infrared region transmits through the organicphotoelectric conversion layer 112. Thus, a signal charge correspondingto the G-component light is generated in the organic photoelectricconversion layer 112 in the pixel 100-2. On the other hand, a signalcharge corresponding to the IR-component light is generated in thephotodiode 115-2.

Further, in the pixel 100-3, a B-component light in the visible lightregion among the lights transmitting through the B color filter 111-3 isabsorbed in the organic photoelectric conversion layer 112 while anIR-component light in the infrared region transmits through the organicphotoelectric conversion layer 112. Thus, a signal charge correspondingto the B-component light is generated in the organic photoelectricconversion layer 112 in the pixel 100-3. On the other hand, a signalcharge corresponding to the IR-component light is generated in thephotodiode 115-3.

An R signal and an IR signal are generated in the pixel 100-1 in thisway. Further, a G signal and an IR signal are generated in the pixel100-2, and a B signal and an IR signal are generated in the pixel 100-3.That is, in the respective pixels 100 two-dimensionally arranged in thepixel array part 11, the IR-component signals are acquired in additionto the signals of color components depending on the type of a colorfilter, thereby generating a visible light image and an IR image at thesame time.

Additionally, the configuration including the organic photoelectricconversion layer 112 configured to generate an R signal is denoted as Rpixel 100-1-R and the configuration including the photodiode 115-1configured to generate an IR signal is denoted as IR pixel 100-1-IR_(R)in the pixel 100-1 in the following description for convenientdescription. That is, the pixel 100-1 may be both the R pixel 100-1-Rand the IR pixel 100-1-IR_(R).

Similarly, the configuration including the organic photoelectricconversion layer 112 configured to generate a G signal is denoted as Gpixel 100-2-G and the configuration including the photodiode 115-2configured to generate an IR signal is denoted as IR pixel 100-2-IR_(G)in the pixel 100-2, That is, the pixel 100-2 may be both the G-pixel100-2-G and the IR pixel 100-2-IR_(G).

Further, the configuration including the organic photoelectricconversion layer 112 configured to generate a B signal is denoted as Bpixel 100-3-B and the configuration including the photodiode 115-3configured to generate an IR signal is denoted as IR pixel 100-3-IR_(B)in the pixel 100-3. That is, the pixel 100-3 may be both the B pixel100-3-B and the IR pixel 100-3-IR_(B).

Further, in a case where the R color filter 111-1, the G color filter111-2, and the B color filter 111-3 do not need to be particularlydiscriminated, they will be simply denoted as color filters 111 in thefollowing description. Further, in a case where the photodiode 115-1,the photodiode 115-2, and the photodiode 115-3 do not need to beparticularly discriminated, they will be simply denoted as photodiodes115. Additionally, the relationships are similarly applied also in theother embodiments described below.

The pixels 100 of FIG. 2 have the above structure, but a spectroscopicshape (spectroscopic characteristics) of an IR pixel in each pixel 100is different depending on the type of a color filter 111 provided in theupper layer, and thus an IR image using the IR signals obtained from allthe IR pixels cannot be generated. The reason will be described below.

(Transmissivity of Color Filters)

Here, FIG. 3 illustrates transmissivity of the color filters 111 of FIG.2 in each wavelength band. In FIG. 3, the horizontal axis indicateswavelength (nm), the value of which is higher from the left side towardthe right side in the Figure. Further, the vertical axis indicatestransmissivity of each color filter 111, the value of which is within arange of 0 to 1.0.

As illustrated in FIG. 3, the R color filter 111-1 has transmissivitycorresponding to a wavelength region (a range of 600 to 650 nm, 550 to650 nm, or the like, for example) of an R-component light in order toextract the R-component light. Further, the G color filter 111-2 hastransmissivity corresponding to a wavelength region (a range of 500 to600 nm, or the like, for example) of a G-component light in order toextract the G-component light. Further, the B color filter 111-3 hastransmissivity corresponding to a wavelength region (a range of 450 to500 nm, 400 to 500 nm, or the like, for example) of a B-component lightin order to extract the B-component light.

Further, as illustrated in FIG. 3, each color filter 111 transmitslights in the regions other than the visible light region, but the Rcolor filter 111-1, the G color filter 111-2, and the B color filter111-3 are different in transmissivity at a wavelength of 700 nm or more,and their transmissivity varies.

(Absorption Rate of Organic Photoelectric Conversion Layer)

FIG. 4 illustrates an absorption rate of the organic photoelectricconversion layer 112 of FIG. 2 in each wavelength band. The horizontalaxis indicates wavelength (nm) and the vertical axis indicatesabsorption rate in FIG. 4.

In FIG. 4, the organic photoelectric conversion layer 112 has anabsorption rate corresponding to a wavelength region (a range of 400 nmto 760 nm, or the like, for example) of lights in the visible lightregion. Additionally, the organic photoelectric conversion layer 112 mayemploy a bulk-hetero structure using P3HT or PCBM, and the like, forexample.

(Absorption Rates of R, G, and B Pixels)

FIG. 5 illustrates absorption rates of the pixels of the respectivecolor components such as the R pixel 100-1-R, the G pixel 100-2-G, andthe B pixel 100-3-B of FIG. 2 in each wavelength band. The horizontalaxis indicates wavelength (nm) and the vertical axis indicatesabsorption rate in FIG. 5.

In FIG. 5, the absorption rate of the R pixel 100-1-R configured of theorganic photoelectric conversion layer 112 corresponds to aspectroscopic shape obtained by multiplying the transmissivity of the Rcolor filter 111-1 of FIG. 3 by the absorption rate of the organicphotoelectric conversion layer 112 of FIG. 4. That is, the R pixel100-1-R has an absorption rate corresponding to the wavelength region (arange of 600 to 650 nm, 550 to 650 nm, or the like, for example) of theR-component light, but does not absorb and transmits lights (infraredrays) with a wavelength outside the wavelength region of the R-componentlight.

Similarly, the absorption rate of the G pixel 100-2-G configured of theorganic photoelectric conversion layer 112 corresponds to aspectroscopic shape obtained by multiplying the transmissivity of the Gcolor filter 111-2 of FIG. 3 by the absorption rate of the organicphotoelectric conversion layer 112 of FIG. 4. That is, the G pixel100-2-G has an absorption rate corresponding to the wavelength region (arange of 500 to 600 nm, or the like, for example) of the G-componentlight, but transmits lights (infrared rays) with a wavelength outsidethe wavelength region of the G-component light.

Further, the absorption rate of the B pixel 100-3-B configured of theorganic photoelectric conversion layer 112 corresponds to aspectroscopic shape obtained by multiplying the transmissivity of the Bcolor filter 111-3 of FIG. 3 by the absorption rate of the organicphotoelectric conversion layer 112 of FIG. 4. That is, the B pixel100-3-B has an absorption rate corresponding to the wavelength region (arange of 450 to 500 nm, 400 to 500 nm, or the like, for example) of theB-component light, but transmits lights with a wavelength outside thewavelength region of the B-component light.

(Transmissivity into IR Pixels)

FIG. 6 illustrates transmissivity into the respective IR pixels of theIR pixel 100-1-IR_(R), the IR pixel 100-2-IR_(G), and the IR pixel100-3-IR_(B) arranged below the color filters 111 of FIG. 2,respectively. The horizontal axis indicates wavelength (nm) and thevertical axis indicates transmissivity in FIG. 6.

In FIG. 6, a light which transmits through the R color filter 111-1 andthe organic photoelectric conversion layer 112 and is detected by(absorbed in) the IR pixel 100-1-IR_(R) configured of the photodiode115-1 is indicated in a wave pattern with “IR_(R)”.

Similarly, in FIG. 6, a light which transmits through the G color filter111-2 and the organic photoelectric conversion layer 112 and is detectedby (absorbed in) the IR pixel 100-2-IR_(G) configured of the photodiode115-2 is indicated in a wave pattern with “IR_(G)”. Further, a lightwhich transmits through the B color filter 111-3 and the organicphotoelectric conversion layer 112 and is detected by (absorbed in) theIR pixel 100-3-IR_(B) configured of the photodiode 115-3 is indicated ina wave pattern with “IR_(B)”.

As illustrated in FIG. 6, a spectrum of the IR-component light absorbedin the IR pixel 100-1-IR_(R), a spectrum of the IR-component lightabsorbed in the IR pixel 100-2-IR_(G), and a spectrum of theIR-component light absorbed in the IR pixel 100-3-IR_(B) are different.Thus, the IR pixel 100-1-IR_(R), the IR pixel 100-2-IR_(G), and the IRpixel 100-3-IR_(B) are different in sensitivity per IR pixel, and cannotbe used as IR pixels for generating the same IR image.

Here, for example, in a case where the pixels 100 illustrated in FIG. 2are two-dimensionally arranged in the Bayer layout in the pixel arraypart 11, they can be expressed as the respective pixels illustrated inFIG. 7. A of FIG. 7 illustrates an R pixel 100-1-R, G pixels 100-2-G,and a B pixel 100-3-B which are configured of the organic photoelectricconversion layer 112 (FIG. 2). That is, the G pixels 100-2-G arecheckerwise arranged and the R pixel 100-1-R and the B pixel 100-3-B arealternately arranged every column in the remaining parts in the pixelarray part 11.

Further, B of FIG. 7 illustrates an IR pixel 100-1-IR_(R), IR pixels100-2-IR_(G), and an IR pixel 100-3-IR_(B) which are configured of thephotodiodes 115 (FIG. 2) embedded in the semiconductor layer 114 belowthe organic photoelectric conversion layer 112 (FIG. 2). In B of FIG. 7,the spectra of the IR-component lights detected by (absorbed in) the IRpixel 100-1-IR_(R), the IR pixels 100-2-IR_(G), and the IR pixel100-3-IR_(B) are different as expressed in contrasting density of therespective IR pixels, and the sensitivity of the respective IR pixels isnot the same.

In a case where the structure of the pixels 100 of FIG. 2 is employed inthis way, the spectrum (spectroscopic shape) of a light detected by(absorbed in) each IR pixel is different depending on the type of acolor filter 111 provided thereon (varies due to a difference intransmissivity of a color filter 111), and thus each IR pixelsubstantially functions as a pixel, for detecting other IR-componentlight. Consequently, an IR image using the IR signals obtained from allthe IR pixels cannot be acquired and a high-resolution IR image cannotbe acquired.

Thus, according to the present technology, a filter functioning as aspectroscopic adjustment layer is provided in order to uniform thespectra (spectroscopic shapes) of the lights detected by (absorbed in)the respective IR pixels provided below the color filters 111 so thatthe spectra of the lights detected by (absorbed in) the respective IRpixels are the same for all the IR pixels. With this arrangement, ahigh-quality visible light image using the RGB signals obtained from,the R pixels, the G pixels, and the B pixels and a high-resolution IRimage using the IR signals obtained from the IR pixels can be acquiredat the same time.

(Structure of Pixels According to First Embodiment)

FIG. 8 is a cross-section view illustrating a structure of the pixels100 according to the first embodiment.

The parts in the pixels 100 of FIG. 8 corresponding to those in thepixels 100 of FIG. 2 are denoted with the same reference numerals, andthe description, thereof will be omitted, as needed. That is, thestructure of the pixels 100 of FIG. 8 is different from that of thepixels 100 of FIG. 2 in that a dual-bandpass filter 141 is providedabove the R color filter 111-1, the G color filter 111-2, and the Bcolor filter 111-3.

The dual-bandpass filter 141 has the transmission bands in the visiblelight region and the infrared region, respectively.

Here, FIG. 9 illustrates transmissivity of the dual-bandpass filter 141in each wavelength band. The horizontal axis indicates wavelength (nm)and the vertical axis indicates transmissivity in FIG. 9. As illustratedin FIG. 9, the dual-bandpass filter 141 has the transmission bands in awavelength region (a range of 400 to 650 nm, or the like, for example)of the visible light region and in a wavelength region (a range of 800to 900 nm, or the like, for example) of the infrared region,respectively, and transmits lights with a wavelength included in thetransmission bands.

The dual-bandpass filter 141 is provided for the pixels 100 so that thespectrum of a light detected by (absorbed in) each IR pixel can be thesame for all the IR pixels by the transmission band in the infraredregion. A difference in transmissivity into each IR pixel before andafter the dual-bandpass filter 141 is inserted will be described herewith reference to FIG. 10 and FIG. 11.

(Characteristics of Each Pixel Before Dual-Bandpass Filter is Inserted)

FIG. 10 is a diagram illustrating characteristics of each pixel beforethe dual-bandpass filter 141 is inserted. Additionally, thecharacteristics of the pixels illustrated in FIG. 10 are thecharacteristics of the pixels before the dual-bandpass filter 141 isinserted, and correspond to the characteristics of the pixels 100illustrated in FIG. 2.

A of FIG. 10 illustrates absorption rates of the pixels of therespective color components configured of the organic photoelectricconversion layer 112 in each wavelength band. As illustrated in A ofFIG. 10, the R pixel 100-1-R can absorb a light (visible light)corresponding to the wavelength region of the R-component light.Further, the G pixel 100-2-G can absorb a light corresponding to thewavelength region of the G-component light, and the B pixel 100-3-B canabsorb a light corresponding to the wavelength region of the B-componentlight.

Further, B of FIG. 10 illustrates transmissivity into the IR pixelsconfigured of the photodiodes 115 arranged below the color filters 111of the respective color components. As illustrated in B of FIG. 10, thespectra of the IR-component lights detected by (absorbed in) the IRpixel 100-1-IR_(R), the IR pixel 100-2-IR_(G), and the IR pixel100-3-IR_(B) are different. That is, the sensitivity is different per IRpixel in the IR pixels, and as described above, the IR pixels cannot beused for generating the same IR image.

Additionally, FIG. 10 illustrates the spectroscopic shapes before thedual-bandpass filter 141 is inserted, and thus A of FIG. 10 illustratesthat the absorption rates of the R pixel 100-1-R, the G pixel 100-2-G,and the B pixel 100-3-B are similar to the absorption rates of the R, G,and B pixels illustrated in FIG. 5. Further, the transmissivity into theIR pixel 100-1-IR_(R), the IR pixel 100-2-IR_(G), and the IR pixel100-3-IR_(B) in B of FIG. 10 is also similar to the transmissivity intothe IR pixels illustrated in FIG. 6.

(Characteristics of Each Pixel After Dual-Bandpass Filter is Inserted)

FIG. 11 is a diagram illustrating characteristics of each pixel afterthe dual-bandpass filter 141 is inserted. Additionally, thecharacteristics of the pixels illustrated in FIG. 11 are thecharacteristics of the pixels after the dual-bandpass filter 141 isinserted, and thus correspond to the characteristics of the pixels 100illustrated in FIG. 8.

A of FIG. 11 illustrates absorption rates of the pixels of therespective color components configured of the organic photoelectricconversion layer 112 in each wavelength band.

Here, in a case where the dual-bandpass filter 141 is provided above thecolor filters 111, the dual-bandpass filter 141 has a transmission bandin a wavelength region (a range of 400 to 650 nm, or the like, forexample) of the visible light region, and thus the organic photoelectricconversion layer 112 can absorb lights in the visible light regiontransmitting through the dual-bandpass filter 141 and the color filters111.

As illustrated in A of FIG. 11, the R pixel 100-1-R can absorb a light(visible light) corresponding to the wavelength region of theR-component light. Further, the G pixel 100-2-G can absorb a lightcorresponding to the wavelength region of the G-component light, and theB pixel 100-3-B can absorb a light corresponding to the wavelengthregion of the B-component light.

Here, with a comparison between A of FIG. 10 and A of FIG. 11, thedual-bandpass filter 141 has a transmission band in the visible lightregion, and thus the organic photoelectric conversion layer 112 whichabsorbs a light in the visible light region can absorb the lights of therespective color components of R component, G component, and B componentirrespective of the presence of the inserted dual-bandpass filter 141.

Further, B of FIG. 11 illustrates transmissivity into the IR pixelsconfigured of the photodiodes 115 arranged below the color filters 111of the respective color components.

Here, in a case where the dual-bandpass filter 141 is provided above thecolor filters 111, the dual-bandpass filter 141 has a transmission handin a wavelength region (a range of 800 to 900 nm, or the like, forexample) of the infrared region, and thus only lights (infrared rays) inthe wavelength region with the transmission band in the infrared regionreach the IR pixel 100-1-IR_(R), the IR pixel 100-2-IR_(G), and the IRpixel 100-3-IR_(B).

Then, the IR-component lights detected by (absorbed in) the IR pixel100-1-IR_(R), the IR pixel 100-2-IR_(G), and the IR pixel 100-3-IR_(B),respectively, correspond to the lights in the wavelength region with thetransmission band in the infrared region of the dual-bandpass filter141. Thus, as illustrated in B of FIG. 11, the spectra of theIR-component lights detected by (absorbed in) the IR pixel 100-1-IR_(R),the IR pixel 100-2-IR_(G), and the IR pixel 100-3-IR_(B) can beuniformed.

With a comparison between B of FIG. 10 and B of FIG. 11, in a case wherethe dual-bandpass filter 141 is not inserted, the spectra of theIR-component lights detected by (absorbed in) the respective IR pixelsvary, but the dual-bandpass filter 141 is inserted so that the spectraof the IR-component lights detected by (absorbed in) the respective IRpixels can be uniformed due to the transmission band in the infraredregion. Consequently, the sensitivity can be uniformed per IR pixel, andthe IR pixels can be used for generating the same IR image.

Here, for example, in a case where the pixels 100 illustrated in FIG. 8are two-dimensionally arranged in the Bayer layout in the pixel arraypart 11, they can be expressed as the respective pixels illustrated inFIG. 12. That is, A of FIG. 12 illustrates an R pixel 100-1-R, G pixels100-2-G, and a B pixel 100-3-B configured of the organic photoelectricconversion layer 112 (FIG. 8). Further, B of FIG. 12 illustrates an IRpixel 100-1-IR_(R), IR pixels 100-2-IR_(G), and an IR pixel 100-3-IR_(B)configured of the photodiodes 115 (FIG. 8) embedded in the semiconductorlayer 114 below the organic photoelectric conversion layer 112 (FIG. 8).

As illustrated in contrasting density of the respective IR pixels in Bof FIG. 12, the spectra of the IR-component lights detected by (absorbedin) the IR pixel 100-1-IR_(R), the IR pixels 100-2-IR_(G), and the IRpixel 100-3-IR_(B) are the same and the sensitivity of the respective IRpixels are the same.

In a case where the structure of the pixels 100 of FIG. 8 is employed inthis way, the lights (visible lights) transmitting through thetransmissionband in the visible light region of the dual-bandpass filter141 are absorbed in the R pixel 100-1-R, the G pixel 100-2-G, and the Bpixel 100-3-B configured of the organic photoelectric conversion layer112 as a photoelectric conversion region. On the other hand, the lights(infrared rays) transmitting through the transmission band in theinfrared region of the dual-bandpass filter 141 are detected by(absorbed in) the IR pixel 100-1-IR_(R), the IR pixel 100-2-IR_(G), andthe IR pixel 100-3-IR_(B) configured of the photodiodes 115-1 to 115-3as photoelectric conversion regions.

At this time, a light (infrared ray) detected by (absorbed in) eachphotodiode 115 is a light in the wavelength region with the transmissionband in the infrared region of the dual-bandpass filter 141. Thus, thespectra of the lights detected by (absorbed in) the respective IR pixelsare the same. Consequently, an IR image using the IR signals obtainedfrom the IR pixels in all the pixels 100 two-dimensionally arranged inthe pixel array part 11 (FIG. 1) can be acquired and a high-resolutionIR image can be acquired.

In addition, a plurality of pixels 100 two-dimensionally arranged in thepixel array part 11 (FIG. 1) are pixels of any color component such as Rpixel 100-1-R, G pixel 100-2-G, or B pixel 100-3-B depending on a layoutpattern such as Bayer layout, and generates any of R signals, G signals,and B signals. Further, at the same time, all the plurality of pixels100 two-dimensionally arranged in the pixel array part 11 (FIG. 1) areIR pixels with the same sensitivity (IR pixel 100-1-IR_(R), IR pixel100-2-IR_(G), or IR pixel 100-3-IR_(B)), and generates IR signals.

As described above, the CMOS image sensor 10 (FIG. 1) having the pixels100 (FIG. 8) according to the first embodiment can acquire a visiblelight image using R signals, G signal, or B signals obtained for aplurality of pixels 100 two-dimensionally arranged in a predeterminedlayout pattern, and a high-resolution IR image using the IR signalsobtained from all the plurality of pixels 100 at the same time.

Further, at this time, the R pixel 100-1-R, the G pixel 100-2-G, or theB pixel 100-3-B which generates an R signal, a G signal, or a B signalphotoelectrically converts a light (visible light) transmitting throughthe organic photoelectric conversion layer 112 and the color filter 111formed above the photodiode 115, and thus can acquire a higher-qualityvisible light image (can keep image quality of a visible light image inusing a conventional Bayer layout, for example) than in a case where aninorganic filter or the like is employed. Consequently, the structure ofthe pixels 100 according to the first embodiment is employed thereby togenerate a high-resolution IR image while keeping high quality of avisible light image.

Additionally, the above description has been made by use of the Bayerlayout as a layout pattern of a plurality of pixels 100two-dimensionally arranged in the pixel array part 11 by way of example,but other layout pattern repeated at a predetermined cycle may beemployed. Further, though not illustrated, on-chip lenses configured tocondense an incident light are actually formed on top of the colorfilters 111 in the structures of the pixels 100 illustrated in FIG. 2and FIG. 8.

<3. Second Embodiment: Structure Using Multilayered Film (OPC: RGBPixels, PD: IR Pixels)>

A structure of pixels 200 according to the second embodiment will bedescribed below with reference to FIG. 13 to FIG. 17.

(Structure of Pixels)

FIG. 13 is a cross-sect ion view illustrating a structure of the pixels200 according to the second embodiment,

FIG. 13 illustrates three pixels 200-1 to 200-3 arranged at arbitrarypositions among a plurality of pixels 200 two-dimensionally arranged inthe pixel array part 11 (FIG. 1). However, the pixels 200-1 to 200-3employ a structure of backside irradiation type.

Additionally, color filters 211 to a wiring layer 216, a transparentelectrode 221 to charge holding parts 224, and wirings 231 in the pixels200 of FIG. 13 correspond to the color filters 111 to the wiring layer116, the transparent electrode 121 to the charge holding parts 124, andthe wirings 131 in the pixels 100 of FIG. 2, respectively.

That is, an organic photoelectric conversion layer 212 which absorbsonly lights in the visible light region is formed above a semiconductorlayer 214 in which photodiodes 215 configured to absorb a light in theinfrared region are formed, and color filters 211 are further formedthereon in the pixels 200 of FIG. 13.

The pixels 200 has the structure illustrated in FIG. 13, and thus an Rpixel 200-1-R, a G pixel 200-2-G, and a B pixel 200-3-B are configuredof the organic photoelectric conversion layer 212. Further, an IR pixel200-1-IR_(R) is configured of a photodiode 215-1 in a pixel 200.Similarly, an IR pixel 200-2-IR_(G) is configured of a photodiode 215-2,and an IR pixel 200-3-IR_(B) is configured of a photodiode 215-3.

Further, in the pixels 200, a multilayered filter 241 is formed betweenthe organic photoelectric conversion layer 212 and an interlayerinsulative film 213. The multilayered filter 241 includes an inorganicmaterial, and has a transmission band at least, in the infrared region.FIG. 14 illustrates a cross-section structure of the multilayered filter241.

In FIG. 14, the multilayered filter 241 is formed in a laminatedstructure of a high refractive index material 241A which is an inorganicmaterial with a high refractive index and a low refractive indexmaterial 241B which is a material with a low refractive index, forexample. The high refractive index material 241A can employ siliconnitride (Si₃N₄), titanium oxide (TiO₂), or the like, for example.Further, the low refractive index material 241B can employ silicon oxide(SiO) or the like, for example.

In FIG. 14, the high refractive index material 241A and the lowrefractive index material 241B are periodically and alternatelylaminated thereby to form the multilayered filter 241. For example, inthe multilayered filter 241, a transmission band can be determineddepending on the thickness of a low refractive index material 241Bformed as an intermediate layer thicker than the other layers.

Here, FIG. 15 illustrates transmissivity of the multilayered filter 241in each wavelength band. The horizontal axis indicates wavelength (nm)and the vertical axis indicates transmissivity in FIG. 15. Asillustrated in FIG. 15, the multilayered filter 241 has the transmissionbands in a wavelength region (a range of 400 to 650 nm, or the like, forexample) of the visible light region and in a wavelength region (a rangeof 800 to 900 nm, or the like, for example) of the infrared region,respectively, and transmits lights with a wavelength included in thetransmission bands.

The multilayered filter 241 is provided in the pixels 200 so that thespectrum of a light absorbed in each IR pixel can be uniformed for allthe IR pixels by the transmission band in the infrared region. Adifference in transmissivity into each IR pixel before and after themultilayered filter 241 is inserted will be described here withreference to FIG. 16 and FIG. 17.

(Characteristics of Each Pixel Before Multilayered Filter is Inserted)

FIG. 16 is a diagram illustrating characteristics of each pixel beforethe multilayered filter 241 is inserted. Additionally, thecharacteristics of the pixels illustrated in FIG. 16 are thecharacteristics of the pixels before the multilayered filter 241 isinserted, and thus correspond to the characteristics of the pixels 100illustrated in FIG. 2.

A of FIG. 16 illustrates absorption rates of pixels of each colorcomponent configured of the organic photoelectric conversion layer 212in each wavelength band. As illustrated in A of FIG. 16, the R pixel200-1-R can absorb a light (visible light) corresponding to thewavelength region of the R-component light. Further, the G pixel 200-2-Gcan absorb a light corresponding to the wavelength region of theG-component light, and the B pixel 200-3-B can absorb a lightcorresponding to the wavelength region of the B-component light.

Further, B of FIG. 16 illustrates transmissivity into the IR pixelsarranged below the color filters 211 of the respective color components.As illustrated in B of FIG. 16, the spectra of the IR-component lightsabsorbed in the IR pixel 200-1-IR_(R), the IR pixel 200-2-IR_(G), andthe IR pixel 200-3-IR_(B) are different. That is, as described above,the IR pixels are different in sensitivity per IR pixel, and thus the IRpixels cannot be used to generate the same IR image.

(Characteristics of Each Pixel After Multilayered Filter is Inserted)

FIG. 17 is a diagram illustrating characteristics of each pixel afterthe multilayered filter 241 is inserted. Additionally, thecharacteristics of the pixels illustrated in FIG. 17 are thecharacteristics of the pixels after the multilayered filter 241 isinserted, and thus correspond to the characteristics of the pixels 200illustrated in FIG. 13.

A of FIG. 17 illustrates absorption rates of pixels of each colorcomponent configured of the organic photoelectric conversion layer 212in each wavelength band. The multilayered filter 241 is formed below theorganic photoelectric conversion layer 212 in the pixels 200 so that thelights absorbed in the R pixel 200-1-R, the G pixel 200-2-G, and the Bpixel 200-3-B do not change before and after the multilayered filter 241is inserted. That is, the waveforms of the absorption rates of the R, G,and B pixels illustrated in A of FIG. 16 are the same as the waveformsof the absorption rates of the R, G, and B pixels illustrated in A ofFIG. 17.

Further, B of FIG. 17 illustrates transmissivity into the IR pixelsarranged below the color filters 211 of the respective color components.

Here, in a case where the multilayered filter 241 is provided below theorganic photoelectric conversion layer 212, the multilayered filter 241has a transmission band in a wavelength region (a range of 800 to 900nm, or the like, for example) of the infrared region, and thus onlylights (infrared rays) in the wavelength region with the transmissionband in the infrared region reach the IR pixel 200-1-IR_(R), the IRpixel 200-2-IR_(G), and the IR pixel 200-3-IR_(B).

In addition, the IR-component lights absorbed in the IR pixel200-1-IR_(R), the IR pixel 200-2-IR_(G), and the IR pixel 200-3-IR_(B),respectively, correspond to the lights in the wavelength region with thetransmission band in the infrared region of the multilayered filter 241.Thus, as illustrated in B of FIG. 17, the spectra of the IR-componentlights detected by the IR pixel 200-1-IR_(R), the IR pixel 200-2-IR_(G),and the IR pixel 200-3-IR_(B), respectively, can be uniformed.

With a comparison between B of FIG. 16 and B of FIG. 17, in a case wherethe multilayered filler 241 is not inserted, the spectra of theIR-component lights absorbed in the respective IR pixels vary, but themultilayered filter 241 is inserted so that the spectra of theIR-component lights absorbed in the respective IR pixels can beuniformed by the transmission band in the infrared region. Consequently,the sensitivity per IR pixel can be uniformed, and the IR pixels can beused to generate the same IR image.

Additionally, the description has been made assuming that themultilayered filter 241 is characterized in that the transmission bandsare provided in both the visible light region and the infrared region inFIG. 15, but a transmission band may be provided only in the infraredregion. That is, the multilayered filter 241 is provided below theorganic photoelectric conversion layer 212 in the pixels 200 so that thelights in the visible light region are sufficiently absorbed in theorganic photoelectric conversion layer 212. Thus, if a transmission bandis not provided in the visible light region in the multilayered filter241 below the organic photoelectric conversion layer 212, a light in thevisible light region does not have an effect on the photodiodes 215below the multilayered filter 241.

Further, the multilayered filter 241 may be characterized in that atransmission band is provided in the infrared region and a light in thevisible light region can be reflected. In this case, in a case where alight in the visible light region which cannot be absorbed in theorganic photoelectric conversion layer 212 reaches the multilayeredfilter 241, the light in the visible light region can reflect toward theorganic photoelectric conversion layer 212 by the multilayered filter241.

Consequently, the organic photoelectric conversion layer 212 can absorbnot only lights in the visible light region above it but also lights inthe visible light region from the multilayered filter 241 below it, andthus the amount of absorbed light in the visible light region can beincreased in the organic photoelectric conversion layer 212. Further,the organic photoelectric conversion layer 212 can increase the amountof absorbed light in the visible light region, and thus can decrease thethickness thereof.

In a case where the structure of the pixels 200 of FIG. 13 is employedin this way, lights (visible lights) transmitting through the respectivecolor filters 211 are absorbed in the R pixel 200-1-R, the G pixel200-2-G, and the B pixel 200-3-B configured of the organic photoelectricconversion layer 212 as a photoelectric conversion region. On the otherhand, lights (infrared rays) transmitting through the transmission bandin the infrared region of the multilayered filter 241 are absorbed inthe IR pixel 200-1-IR_(R), the IR pixel 200-2-IR_(G), and the IR pixel200-3-IR_(B) configured of the photodiodes 215-1 to 215-3 asphotoelectric conversion regions.

At this time, a light (infrared ray) absorbed in each photodiode 215 isa light in the wavelength region with the transmission band in theinfrared region of the multilayered filter 241. Thus, the spectra of thelights absorbed in the respective IR pixels are uniformed. Consequently,an IR image using the IR signals obtained from the IR pixels in all thepixels 200 two-dimensionally arranged in the pixel array part 11(FIG. 1) can be acquired, and a high-resolution IR image can beacquired.

Then, a plurality of pixels 200 two-dimensionally arranged in the pixelarray part 11 (FIG. 1) are pixels of any color component such as R pixel200-1-R, G pixel 200-2-G, or B pixel 200-3-B depending on a layoutpattern such as Bayer layout, thereby generating any of R signals, Gsignals, and B signals. Further, at the same time, all the plurality ofpixels 200 two-dimensionally arranged in the pixel array part 11(FIG. 1) are IR pixels with the same sensitivity (IR pixel 200-1-IR_(R),IR pixel 200-2-IR_(G), or IR pixel 200-3-IR_(B)) thereby to generate IRsignals.

As described above, the CMOS image sensor 10 (FIG. 1) having the pixels200 (FIG. 13) according to the second embodiment can acquire a visiblelight image using R signals, G signals, or B signals obtained for aplurality of pixels 200 two-dimensionally arranged in a predeterminedlayout pattern, and a high-resolution IR image using the IR signalsobtained from all the plurality of pixels 200 at the same time.

Further, at this time, the R pixel 200-1-R, the G pixel 200-2-G, or theB pixel 200-3-B which generates an R signal, a G signal, or a B signalphotoelectrically converts a light (visible light) transmitting throughthe organic photoelectric conversion layer 212 and the color filter 211formed above the photodiode 215, thereby acquiring a high-qualityvisible light image. Consequently, the structure of the pixels 200according to the second embodiment is employed thereby to generate ahigh-resolution IR image while keeping high quality of a visible lightimage.

<4. Third Embodiment: Structure Using Plasmon Filter (OPC: RGB Pixels,PD: IR Pixels)>

A structure of pixels 300 according to the third embodiment will bedescribed below with reference to FIG. 18 and FIG. 19.

(Structure of Pixels)

FIG. 18 is a cross-section view illustrating a structure of the pixels300 according to the third embodiment.

FIG. 18 illustrates three pixels 300-1 to 300-3 arranged at arbitrarypositions among a plurality of pixels 300 two-dimensionally arranged inthe pixel array part 11 (FIG. 1) byway of example. However, the pixels300-1 to 300-3 employ a structure of backside irradiation type.

Additionally, color filters 311 to a wiring layer 316, a transparentelectrode 321 to charge holding parts 324, and wirings 331 in the pixels300 of FIG. 18 correspond to the color filters 111 to the wiring layer116, the transparent electrode 121 to the charge holding parts 124, andthe wirings 131 in the pixels 100 of FIG. 2, respectively.

That is, in the pixels 300 of FIG. 18, an organic photoelectricconversion layer 312 configured to absorb only lights in the visiblelight region is formed above a semiconductor layer 314 in whichphotodiodes 315 as photoelectric conversion regions are formed, and thecolor filters 311 are further formed thereon.

The pixels 300 employ the structure illustrated in FIG. 18 so that an Rpixel 300-1-R, a G pixel 300-2-G, and a B pixel 300-3-B are configuredof the organic photoelectric conversion layer 312. Further., an IR pixel300-1-IR_(R) is configured of a photodiode 315-1 in a pixel 300.Similarly, an IR pixel 300-2-IR_(G) is configured of a photodiode 315-2and an IR pixel 300-3-IR_(B) is configured of a photodiode 315-3.

Further, a plasmon filter 341 is formed between the organicphotoelectric conversion layer 312 and the semiconductor layer 314 inthe pixels 300. The plasmon filter 341 is a metal thin-film filter usingsurface plasmon polar it on (SPP), and has a transmission band at leastin the infrared region. FIG. 19 illustrates a structure of the plasmonfilter 341.

In FIG. 19, the plasmon filter 341 is configured in which holes 341Bhaving an opening with a predetermined diameter are arranged for a metalthin-film 341A in a honeycomb structure. The metal thin-film 341Aincludes a metal such as aluminum (Al), gold (Au), or silver (Ag), analloy, or the like, for example. Further, the diameter of the opening ofthe hole 341B is as large as a photodiode 315 formed in thesemiconductor layer 314 can detect a light within a certain wavelengthregion in the infrared region. Additionally, a material such as siliconnitride (SiN) can be embedded inside the holes 341B.

Additionally, the arrangement of the holes 341B in the plasmon filter341 is not limited to the honeycomb structure illustrated in FIG. 19,but may be any periodic arrangement such as arrangement having anorthogonal matrix (square matrix) structure, and the like. Further, themicrostructural pattern of the plasmon filter 341 may be a ring-shaped,dot-shaped pattern, or the like, for example, in addition to a structurein which the holes 341B are arranged illustrated in FIG. 19. That is,the plasmon filter 341 can be a metal thin-film filter in which at leastone periodic microstructural pattern is formed for the metal thin-film.

In a case where the structure of the pixels 300 of FIG. 18 is employedin this way, lights (visible lights) transmitting through the respectivecolor filters 311 are absorbed in the R pixel 300-1-R, the G pixel300-2-G, and the B pixel 300-3-B configured of the organic photoelectricconversion layer 312 as a photoelectric conversion region. On the otherhand, lights (infrared rays) transmitting through the plasmon filter 341are absorbed in the IR pixel 300-1-IR_(R), the IR pixel 300-2-IR_(G),and the IR pixel 300-3-IR_(B) configured of the photodiodes 315-1 to315-3 as photoelectric conversion regions, respectively.

At this time, a light (infrared ray) absorbed in each IR pixel configureof each photodiode 315 is a light in a certain wavelength region in theinfrared region transmitting through the plasmon filter 341. Thus, thespectra of the lights absorbed in the respective IR pixels are the same.Consequently, an IR image using the IR signals obtained from the IRpixels in all the pixels 300 two-dimensionally arranged in the pixelarray part 11 (FIG. 1) can be acquired, and a high-resolution IR imagecan be acquired.

Then, a plurality of pixels 300 two-dimensionally arranged in the pixelarray part 11 (FIG. 1) are pixels of any color component such as R pixel300-1-R, G pixel 300-2-G, or B pixel 300-3-B depending on a layoutpattern such as Bayer layout thereby to generate any of R signals, Gsignals, and B signals. Further, at the same time, all the plurality ofpixels 300 two-dimensionally arranged in the pixel array part 11 (FIG. 1) are IR pixels with the same sensitivity (IR pixel 300-1-IR_(R), IRpixel 300-2-IR_(G), or IR pixel 300-3-IR_(B)) thereby to generate IRsignals.

As described above, the CMOS image sensor 10 (FIG. 1) having the pixels300 (FIG. 18) according to the third embodiment can acquire a visiblelight image using R signals, G signals, or B signals obtained for aplurality of pixels 300 two-dimensionally arranged in a predeterminedlayout pattern and a high-resolution IR image using the IR signalsobtained from all the plurality of pixels 300 at the same time.

Further, at this time, the R pixel 300-1-R, the G pixel 300-2-G, or theB pixel 300-3-B configured to generate an R signal, a G signal, or a Bsignal photoelectrically converts a light (visible light) transmittingthrough the organic photoelectric conversion layer 312 and the colorfilter 311 formed above the photodiode 315, thereby acquiring ahigh-quality visible light image. Consequently, the structure of thepixels 300 according to the third embodiment is employed thereby togenerate a high-resolution IR image while keeping high quality of avisible light image.

Additionally, the plasmon filter 341 is employed as a filter having atransmission band at least in the infrared region according to the thirdembodiment, and is advantageous in that the manufacturing steps areeasier than in a case where the multilayered filter 241 having thesimilar characteristics is employed. That is, in a case where themultilayered filter 241 is employed, a step of manufacturing amultilayered film with different refractive indexes is required onmanufacture, while the step is not required on manufacture in a casewhere the plasmon filter 341 is employed, and thus the manufacturingsteps are easier in terms of the point.

<5. Fourth Embodiment: Structure Using Dual-Bandpass Filter (OPC: IRPixels, PD: RGB Pixels)>

A structure of pixels 400 according to the fourth embodiment will bedescribed below with reference to FIG. 20 to FIG. 23.

(Structure of Pixels)

FIG. 20 is a cross-section view illustrating a structure of the pixels400 according to the fourth embodiment.

FIG. 20 illustrates three pixels 400-1 to 400-3 arranged at arbitrarypositions among a plurality of pixels 400 two-dimensionally arranged inthe pixel array part 11 (FIG. 1) by way of example. However, the pixels400-1 to 400-3 employ a structure of backside irradiation type.

Additionally, color filters 411 to a wiring layer 416, a transparentelectrode 421 to charge holding parts 424, and wirings 431 in the pixels400 of FIG. 20 correspond to the color filters 111 to the wiring layer116, the transparent electrode 121 to the charge holding parts 124, andthe wirings 131 in the pixels 100 of FIG. 2, respectively.

That is, in the pixels 400 of FIG. 20, an organic photoelectricconversion layer 412 configured to absorb only lights in the infraredregion is formed above a semiconductor layer 414 in which photodiodes415 as photoelectric conversion regions are formed, and the colorfilters 411 are further formed thereon. Additionally, a photoelectricconversion material in the infrared region of the organic photoelectricconversion layer 412 can employ a bulk-hetero structure in a combinationof chloroaluminum phthalocyanine (ClAlPc) absorbent in the infraredregion and transparent organic semiconductor, for example.

The pixels 400 have the structure illustrated in FIG. 20, and thus an IRpixel 400-1-IR_(R), an IR pixel 400-2-IR_(G), and an IR pixel 400-3-IR 3are configured of the organic photoelectric conversion layer 412.Further, in the pixels 400, an R pixel 400-1-R is configured of aphotodiode 415-1. Similarly, a G pixel 400-2-G is configured of aphotodiode 415-2, and a B pixel 400-3-B is configured of a photodiode415-3.

Further, in the pixels 400, a dual-bandpass filter 441 is formed abovethe color filters 411. The dual-bandpass filter 441 has transmissionbands in the visible light region and in the infrared region,respectively, similarly to the dual-bandpass filter 141 of FIG. 8. Asillustrated in FIG. 21, the dual-bandpass filter 441 has thetransmission bands in a wavelength region (a range of 400 to 650 nm, orthe like, for example) of the visible light region and in a wavelengthregion (a range of 800 to 900 nm, or the like, for example) of theinfrared region, respectively.

The dual-bandpass filter 441 is provided in the pixels 400 so that thespectrum of a light absorbed in each IR pixel can be the same for allthe IR pixels due to the transmission band in the infrared region. Adifference in transmissivity into each IR pixel before and after thedual-bandpass filter 441 is inserted will be described here withreference to FIG. 22 and FIG. 23.

(Characteristics of Each Pixel Before Dual-Bandpass Filter is Inserted)

FIG. 22 is a diagram for explaining characteristics of each pixel beforethe dual-bandpass filter 441 is inserted.

A of FIG. 22 illustrates an absorption rate of the organic photoelectricconversion layer 412 in each wavelength band. As illustrated in A ofFIG. 22, the organic photoelectric conversion layer 412 absorbs lights(infrared rays) corresponding to a wavelength region (wavelength regionwith a certain width) of an IR-component light, and thus infrared raysin the wavelength region with a certain width are absorbed in the IRpixel 400-1-IR_(R), the IR pixel 400-2-IR_(G), and the IR pixel400-3IR_(B).

Further, B of FIG. 22 illustrates transmissivity of the color filters411 of the respective color components in each wavelength band. Thetransmi ssivity into the R, G, and B pixels configured of thephotodiodes 415 arranged below the color filters 411 corresponds to thelights transmitting through the color filters 411 having thecharacteristics of B of FIG. 22 and the organic photoelectric conversionlayer 412 having the characteristics of A of FIG. 22. The transmittedlights (visible lights) are then absorbed in the R pixel 400-1-R, the Gpixel 400-2-G, and the B pixel 400-3-B,

(Characteristics of Each Pixel After Dual-Bandpass Filter is Inserted)

FIG. 23 is a diagram illustrating characteristics of each pixel afterthe dual-bandpass filter 441 is inserted. Additionally, thecharacteristics of the pixels illustrated in FIG. 23 are thecharacteristics of the pixels after the dual-bandpass filter 441 isinserted, and thus correspond to the characteristics of the pixels 400illustrated in FIG. 20.

A of FIG. 2 3 illustrates an absorption rate of the IR pixels configuredof the organic photoelectric conversion layer 412 in each wavelengthband.

Here, in a case where the dual-bandpass filter 441 is provided above thecolor filters 411, the dual-bandpass filter 441 has a transmission bandin a wavelength region (a range of 800 to 900 nm, or the like, forexample) of the infrared region, and thus only lights (infrared rays) inthe wavelength region with the transmission band in the infrared regionare absorbed in the IR pixel 400-1-IR_(R), the IR pixel 400-2-IR_(G),and the IR pixel 400-3-IR_(B).

Further, B of FIG. 23 illustrates transmissivity into the R, G, and Bpixels configured of the photodiodes 415 arranged below the colorfilters 411 of the respective color components.

Here, in a case where the dual-bandpass filter 441 is provided above thecolor filters 411, the dual-bandpass filter 441 has a transmission bandin a wavelength region (a range of 400 to 650 nm, or the like, forexample) of the visible light region, and thus lights (visible lights)transmitting through the dual-bandpass filter 441 and the organicphotoelectric conversion layer 412 are absorbed in the R pixel 400-1-R,the G pixel 400-2-G, and the B pixel 400-3-B.

As illustrated in B of FIG. 23, the R pixel 400-1-R can absorb a light(visible light) corresponding to the wavelength region of theR-component light. Further, the G pixel 400-2-G can absorb a lightcorresponding to the wavelength region of the G-component light, and theB pixel 400-3-B can absorb a light corresponding to the wavelengthregion of the B-component light.

In a case where the structure of the pixels 400 of FIG. 20 is employedin this way, lights (infrared rays) transmitting through thetransmission band in the infrared region of the dual-bandpass filter 441are absorbed in the IR pixel 400-1-IR_(R), the IR pixel 400-2-IR_(G),and the IR pixel 400-3-IR_(B) configured of the organic photoelectricconversion layer 412 as a photoelectric conversion region. On the otherhand, lights (visible lights) transmitting through the transmission bandin the visible light region of the dual-bandpass filter 441 are absorbedin the R pixel 400-1-R, the G pixel 400-2-G, and the B pixel 400-3-Bconfigured of the photodiodes 415-1 to 415-3 as photoelectric conversionregions.

At this time, a light (infrared ray) absorbed in each IR pixelconfigured of the organic photoelectric conversion layer 412 is a lightin the wavelength region with the transmission band in the infraredregion of the dual-bandpass filter 441. Thus, the spectra of the lightsabsorbed in the respective IR pixels are the same. Consequently, an IRimage using the IR signals obtained from the IR pixels in all the pixels400 two-dimensionally arranged in the pixel array part 11 (FIG. 1) canbe acquired, and a high-resolution IR image can be acquired.

A plurality of pixels 400 two-dimensionally arranged in the pixel arraypart 11 (FIG. 1) are then pixels of any color component such as R pixel400-1-R, G pixel 400-2-G, or B pixel 400-3-B depending on a layoutpattern such as Bayer layout thereby to generate any of R signals, Gsignal, and B signals. Further, at the same time, all the plurality ofpixels 400 two-dimensionally arranged, in the pixel array part 11(FIG. 1) are IR pixels with the same sensitivity (IR pixel 400-1-IR_(R),IR pixel 400-2-IR_(G), or IR pixel 400-3-IR_(B)) thereby to generate IRsignals.

As described above, the CMOS image sensor 10 (FIG. 1) having the pixels400 (FIG. 20) according to the fourth embodiment can acquire a visiblelight image using R signals, G signals, or B signals obtained for aplurality of pixels 400 two-dimensionally arranged in a predeterminedlayout pattern, and a high-resolution IR image using the IR signalsobtained from all the plurality of pixels 400 at the same time.

Further, at this time, the R pixel 400-1-R, the G pixel 400-2-G, or theB pixel 400-3-B which generates an R signal, a G signal, or a B signalphotoelectrically converts a light (visible light) transmitting throughthe organic photoelectric conversion layer 412 and the color filter 411formed above the photodiode 415, thereby acquiring a high-qualityvisible light image. Consequently, the structure of the pixels 400according to the fourth embodiment is employed thereby to generate ahigh-resolution IR image while keeping high quality of a visible lightimage.

<6. Fifth Embodiment: Structure Using Multilayered Filter (OPC: IRPixels, PD: RGB Pixels)>

A structure of pixels 500 according to the fifth embodiment will befinally described with reference to FIG. 24 and FIG. 25.

(Structure of Pixels)

FIG. 24 is a cross-section view illustrating a structure of the pixels500 according to the fifth embodiment.

FIG. 24 illustrates three pixels 500-1 to 500-3 arranged at arbitrarypositions among a plurality of pixels 500 two-dimensionally arranged inthe pixel array part 11 (FIG. 1) byway of example. However, the pixels500-1 to 500-3 employ a structure of backside irradiation type.

Additionally, color filters 511 to a wiring layer 516, a transparentelectrode 521 to charge holding parts 524, and wirings 531 in the pixels500 of FIG. 24 correspond to the color filters 111 to the wiring layer116, the transparent electrode 121 to the charge holding parts 124, andthe wirings 131 in the pixels 100 of FIG. 2, respectively.

That is, in the pixels 500 of FIG. 24, an organic photoelectricconversion layer 512 which absorbs only lights in the infrared regionsis formed above a semiconductor layer 514 in which photodiodes 515 asphotoelectric conversion regions are formed, and the color filters 511are further formed thereon. Additionally, a photoelectric conversionmaterial of the infrared region of the organic photoelectric conversionlayer 512 can employ a bulk-hetero structure similarly to the organicphotoelectric conversion layer 412 of FIG. 20.

The pixels 500 have the structure illustrated in FIG. 24, and thus an IRpixel 500-1-IR_(R), an IR pixel 500-2-IR_(G), and an IR pixel500-3-IR_(B) are configured of the organic photoelectric conversionlayer 512. Further, in the pixels 500, an R pixel 500-1-R is configuredof a photodiode 515-1. Similarly, a G pixel 500-2-G is configured of aphotodiode 515-2, and a B pixel 500-3-B is configured of a photodiode515-3.

Further, a multilayered filter 541 is formed between the color filters511 and the organic photoelectric conversion layer 512 in the pixels500. The multilayered filter 541 has transmission bands in the visiblelight region and the infrared region, respectively, similarly to themultilayered filter 241 of FIG. 13. As illustrated in FIG. 25, themultilayered filter 541 has the transmission bands in a wavelengthregion (a range of 400 to 650 nm, or the like, for example) of thevisible light region and in a wavelength region (a range of 800 to 900nm, or the like, for example) of the infrared region, respectively.

In a case where the structure of the pixels 500 of FIG. 24 is employedin this way, lights (infrared rays) transmitting through thetransmission band in the infrared region of the multilayered filter 541are absorbed in the IR pixel 500-1-IR_(R), the IR pixel 500-2-IR_(G),and the IR pixel 500-3-IR_(B) configured of the organic photoelectricconversion layer 512 as a photoelectric conversion region. On the otherhand, lights (visible lights) transmitting through the transmission bandin the visible light region of the multilayered filter 541 are absorbedin the R pixel 500-1-R, the G pixel 500-2-G, and the B pixel 500-3-Bconfigured of the photodiodes 515-1 to 515-3 as photoelectric conversionregions, respectively.

At this time, a light (infrared ray) absorbed in each IR pixelconfigured of the organic photoelectric conversion layer 512 is a lightin the wavelength region with the transmission band in the infraredregion of the multilayered filter 541. Thus, the spectra of the lightsabsorbed in the respective IR pixels are the same. Consequently, an IRimage using the IR signals obtained from the IR pixels in all the pixels500 two-dimensionally arranged in the pixel array part 11 (FIG. 1) canbe acquired, and a high-resolution IR image can be acquired.

A plurality of pixels 500 two-dimensionally arranged in the pixel arraypart 11 (FIG. 1) are then pixels of any color component such as R pixel500-1-R, G pixel 500-2-G, or B pixel 500-3-B depending on a layoutpattern such as Bayer layout thereby to generate any of R signals, Gsignals, and B signals. Further, at the same time, all the plurality ofpixels 500 two-dimensionally arranged in the pixel array part 11(FIG. 1) are IR pixels with the same sensitivity (IR pixel 500-1-IR_(R),IR pixel 500-2-IR_(G), or IR pixel 500-3-IR_(B)) thereby to generate IRsignals.

As described above, the CMOS image sensor 10 (FIG. 1) having the pixels500 (FIG. 24) according to the fifth embodiment can acquire a visiblelight image using R signals, G signals, or B signals obtained for aplurality of pixels 500 two-dimensionally arranged in a predeterminedlayout pattern, and a high-resolution IR image using the IR signalsobtained from all the plurality of pixels 500 at the same time.

Further, at this time, the R pixel 500-1-R, the G pixel 500-2-G, or theB pixel 500-3-B which generates an R signal, a G signal, or a B signalphotoelectrically converts a light (visible light) transmitting throughthe organic photoelectric conversion layer 512 and the color filter 511formed above the photodiode 515 thereby to acquire a high-qualityvisible light image. Consequently, the structure of the pixels 500according to the fifth embodiment is employed thereby to generate ahigh-resolution IR image while keeping high quality of a visible lightimage.

<7. Readout Circuit>

A readout circuit in a pixel according to the first embodiment to thefifth embodiment will be described below with reference to FIG. 26 andFIG. 27. A circuit for reading out signal charges obtained by theorganic photoelectric conversion layer 112 and a circuit for reading outsignal charges obtained by the photodiode 115 in a pixel 100 (FIG. 8)according to the first embodiment will be described here by way ofexample.

However, a readout circuit for the organic photoelectric conversionlayer 112 employs a system in which a memory part is provided forreducing noises and a system in which a feedback amplifier is providedto feedback a signal. A readout circuit employing the latter feedbacksystem will be described here.

(Readout Circuit for Organic Photoelectric Conversion Layer)

FIG. 2 6 is a diagram illustrating a readout circuit for the organicphotoelectric conversion layer 112 in a pixel 100 (FIG. 8).

In FIG. 26, a pixel 100 has a pixel circuit (readout circuit) configuredof a FD part 171, a reset transistor 172, an amplification transistor173, and a select transistor 174 in addition to the organicphotoelectric conversion layer 112. The pixel 100 is further providedwith a feedback amplifier 175 for feeding back a readout signal to areset signal for the pixel circuit.

Further, a plurality of drive lines as pixel drive lines 21 (FIG. 1) arewired per row of pixels, for example, for the pixels 100. Various drivesignals SEL and RST are then supplied via a plurality of drive linesfrom the vertical drive circuit 12 (FIG. 1).

The organic photoelectric conversion layer 112 is a photoelectricconversion region which absorbs only lights in the visible light regionand generates signal charges (charges) corresponding to a light of eachcolor component such as R component, G component, or B component.

The FD part 171 is connected between the organic

photoelectric conversion layer 112 and the amplification transistor 173.The FD part 171 is floating diffusion (FD), charge/voltage-convertssignal charges generated by the organic photoelectric conversion layer112 into a voltage signal, and outputs the voltage signal to theamplification transistor 173.

The amplification transistor 173 is connected at its gate electrode tothe FD part 171, is connected at its drain electrode to the power supplypart, and serves as an input part of a circuit for reading out a voltagesignal held in the FD part 171 or a source follower circuit. That is,the amplification transistor 173 is connected at its source electrode toa vertical signal line 22 (FIG. 1) via the select transistor 174 therebyto configure a constant current source connected to one end of thevertical signal line 22, and a source follower circuit.

The select transistor 174 is connected between the source electrode ofthe amplification transistor 173 and the vertical signal line 22 (FIG.1). A drive signal SEL is applied to the gate electrode of the selecttransistor 174. When the drive signal SEL enters the active state, theselect transistor 174 enters the conducted state and the pixel 100 is inthe selected state. With this arrangement, a readout signal (pixelsignal) output from the amplification transistor 173 is output to thevertical signal line 22 (FIG. 1) via the select transistor 174.

The reset transistor 172 is connected between the FD part 171 and thepower supply part. A drive signal RST is applied to the gate electrodeof the reset transistor 172. When the drive signal RST enters the activestate, the reset gate of the reset transistor 172 enters the conductedstate and a reset signal for resetting the FD part 171 is supplied tothe FD part 171.

The feedback amplifier 175 is connected at one input terminal (−) to thevertical signal line 22 connected to the select transistor 174, and isconnected at the other input terminal (+) to a reference voltage part(Vref). Further, the output terminal of the feedback amplifier 175 isconnected between the reset transistor 172 and the power supply part.The feedback amplifier 175 feeds back a readout signal (pixel signal)from the pixel 100 to a reset signal by the reset transistor 172.

Specifically, in a case where the reset transistor 172 resets the FDpart 171, the drive signal RST enters the active state and the resetgate enters the conducted state. At this time, the feedback amplifier175 gives a necessary gain to and feeds back an output signal of theselect transistor 174 and feeds back thereby to cancel noises at theinput part of the amplification transistor 173.

The readout circuit for the organic photoelectric conversion layer 112in the pixel 100 is configured as described above.

Additionally, FIG. 2 6 illustrates the readout circuit for the organicphotoelectric conversion layer 112 in the pixel 100 (FIG. 8) accordingto the first embodiment by way of example, but a readout circuit for theorganic photoelectric conversion layers 212 to 512 can be configuredsimilarly also in a pixel 200 to apixel 500 according to the otherembodiments. However, according to the fourth embodiment, or the fifthembodiment, the organic photoelectric conversion layer 412 or 512absorbs only lights in the infrared region and generates signal charges.

(Readout Circuit for Photodiode)

FIG. 27 is a diagram illustrating a readout circuit for a photodiode 115in a pixel 100 (FIG. 8).

In FIG. 27, a pixel 100 has a pixel circuit (readout circuit) configuredof a transfer transistor 181, a FD part 182, a reset transistor 183, ansimplification transistor 184, and a select transistor 185 in additionto the photodiode 115. Further, a plurality of drive lines as pixeldrive lines 21 (FIG. 1) are wired per row of pixels, for example, in thepixels 100. Various drive signals TG, SEL, and RST are then supplied viaa plurality of drive lines from the vertical drive circuit 12 (FIG. 1).

The photodiode 115 is a photoelectric conversion region including apn-junction photodiode, for example. The photodiode 115 generates andaccumulates signal charges (charges) depending on the amount of receivedlight.

The transfer transistor 181 is connected between the photodiode 115 andthe FD part 182. A drive signal TG is applied to the gate electrode ofthe transfer transistor 181. When the drive signal TG enters the activestate, the transfer gate of the transfer transistor 181 enters theconducted state, and the signal charges accumulated in the photodiode115 are transferred to the FD part 182 via the transfer transistor 181.

The FD part 182 is connected between the transfer transistor 181 and theamplification transistor 184. The FD part 182 is floating diffusion(FD), charge/voltage-converts the signal charges transferred by thetransfer transistor 181 into a voltage signal, and outputs the voltagesignal to the amplification transistor 184.

The reset transistor 183 is connected between the FD part 182 and thepower supply part. A drive signal RST is applied to the gate electrodeof the reset transistor 183. When the drive signal RST enters the activestate, the reset gate of the reset transistor 183 enters the conductedstate, and the potential of the FD part 182 is reset at a level of thepower supply part.

The amplification transistor 184 is connected at its gate electrode tothe FD part 182, is connected at its drain electrode to the power supplypart, and serves as an input part of a circuit for reading out a voltagesignal held in the FD part 182 or a source follower circuit. That is,the amplification transistor 184 is connected at its source electrode tothe vertical signal line 22 (FIG. 1) via the select transistor 185thereby to configure a constant current source connected to one end ofthe vertical signal line 22, and a source follower circuit.

The select transistor 185 is connected between the source electrode ofthe amplification transistor 184 and the vertical signal line 22 (FIG.1). A drive signal SEL is applied to the gate electrode of the selecttransistor 185. When the drive signal SEL enters the active state, theselect transistor 185 enters the conducted state and the pixel 100 is inthe selected state. With this arrangement, a readout signal (pixelsignal) output from the amplification transistor 184 is output to thevertical signal line 22 (FIG. 1) via the select transistor 185.

The readout circuit for the photodiode 115 in the pixel 100 isconfigured as described above.

Additionally, FIG. 27 illustrates the readout circuit for the photodiode115 in the pixel 100 (FIG. 8) according to the first embodiment by wayof example, but a readout circuit for the photodiodes 215 to 515 can beconfigured similarly also in a pixel 200 to a pixel 500 according to theother embodiments. However, according to the first embodiment to thethird embodiment, the photodiodes 115 to 315 are IR pixels. Further,according to the fourth embodiment and the fifth embodiment, thephotodiodes 415 to 515 are pixels corresponding to each color component.

The readout circuits in a pixel according to the first embodiment to thefifth embodiment have been described above, but in a case where thereadout circuit for the organic photoelectric conversion layer employsthe feedback system as illustrated in FIG. 26, a memory part does notneed to be provided, but the feedback system is disadvantageous inreadout speed and is characterized in that reset noises (kTC noises)cannot be completely removed.

On the other hand, a limited readout speed or reset noises may befurther permitted in generating an IR image than in generating a visiblelight image. For example, a light (IR light) in the infrared region isapplied on an object by use of an external IR light source in generatingan IR image thereby to secure sufficient sensitivity, and thus theproblem is eliminated even if reset noises cannot be completely removed.Further, limited fast readout may be permitted depending on anapplication of an IR image.

With this arrangement, in a case where the organic photoelectricconversion layer absorbs only lights in the infrared region andgenerates signal charges, a readout circuit for the organicphotoelectric conversion layer can employ the readout circuit in thefeedback system illustrated in FIG. 26. In this case, a readout circuitfor a photodiode employs the readout circuit illustrated in FIG. 27thereby to read out RGB signals at a high speed and at low noises.

That is, a combination of the readout circuit for the organicphotoelectric conversion layer illustrated in FIG. 26 and the readoutcircuit for the photodiode illustrated in FIG. 27 is preferably appliedto pixels in which IR pixels are configured of an organic photoelectricconversion layer and RGB pixels are configured of photodiodes. Thus, thepixels 400 according to the fourth embodiment and the pixels 500according to the fifth embodiment among the pixels according to thefirst embodiment to the fifth embodiment have the structure suitable forthe combination of the readout circuits illustrated in FIG. 26 and FIG.27.

However, the combination of the readout circuits illustrated in FIG. 26and FIG. 27 is exemplary, and, for example, a readout circuit for anorganic photoelectric conversion layer which absorbs only lights in thevisible light region in the pixels 100 to 300 according to the firstembodiment to the third embodiment employs a readout circuit providedwith a memory part for reducing noises, for example, thereby reading outRGB signals at low noises. Additionally, the readout circuit for theorganic photoelectric conversion layer illustrated in FIG. 26 may be ofcourse employed for the pixels 100 to 300 according to the firstembodiment to the third embodiment.

That is, the combination of the readout, circuits illustrated in FIG. 26and FIG. 27 is exemplary, and any combination of a readout circuitcapable of reading out signal charges photoelectrically converted by anorganic photoelectric conversion layer and a readout circuit capable ofreading out signal charges photoelectrically converted by a photodiodemay be employed. Additionally, a readout circuit for an organicphotoelectric conversion layer may be the same as a readout circuit fora photodiode.

<8. Variants

(Other Structure of Pixels)

The description has been made assuming that the pixels according to thefirst embodiment to the fifth embodiment are in a structure of backsideirradiation type, but a structure of surface irradiation type may beemployed. FIG. 28 illustrates that the pixels 100 (FIG. 8) according tothe first embodiment are in a structure of surface irradiation type. Thewiring layer 116 is formed on the semiconductor layer 114 in the pixels100 of surface irradiation type in FIG. 28.

Similarly, FIG. 29 to FIG. 32 illustrate that the pixels 200 (FIG. 13)according to the second embodiment, the pixels 300 (FIG. 18) accordingto the third embodiment, the pixels 400 (FIG. 20) according to thefourth embodiment, and the pixels 500 (FIG. 24) according to the fifthembodiment are in the structure of surface irradiation type.

(Other Exemplary Filter)

The description has been made byway of the dual-bandpass filter 141(FIG. 8), the multilayered filter 241 (FIG. 13), the plasmon filter 341(FIG. 18), the dual-bandpass filter 441 (FIG. 20), and the multilayeredfilter 541 (FIG. 24) as a filter functioning as a spectroscopicadjustment layer in the pixels according to the first embodiment to thefifth embodiment, but the filters are exemplary and other filter havinga similar spectroscopic adjustment function may be employed.

For example, an anti-UV filter which transmits a light in apredetermined wavelength region may be employed instead of thedual-bandpass filter 141 or the dual-bandpass filter 441. Further, forexample, the multilayered filter 241, the plasmon filter 341, and themultilayered filter 541 are exemplary filters having a transmission bandat least in the infrared region, and other filter having a transmissionband in the infrared region may be employed.

<9. Configuration of Electronic Apparatus>

FIG. 33 is a diagram illustrating an exemplary configuration of anelectronic apparatus having a solid-state imaging apparatus.

An electronic apparatus 1000 of FIG. 33 is, for example, an imagingapparatus such as digital still camera or video camera, a portableterminal apparatus having an imaging function such as Smartphone ortablet terminal, or the like.

In FIG. 33, the electronic apparatus 1000 is configured of a solid-stateimaging apparatus 1001, a digital signal processor (DSP) circuit 1002, aframe memory 1003, a display part 1004, a recording part 1005, anoperation part 1006, and a power supply part 1007. Further, the DSPcircuit 1002, the frame memory 1003, the display part 1004, therecording part 1005, the operation part 1006, and the power supply part1007 are mutually connected via a bus line 1008 in the electronicapparatus 1000.

The solid-state imaging apparatus 1001 corresponds to the CMOS imagesensor 10 of FIG. 1, and a structure of the pixels two-dimensionallyarranged in the pixel array part 11 therein employs a structure ofpixels corresponding to any of the first embodiment to the fifthembodiment, for example.

The DSP circuit 1002 is a signal processing circuit configured toprocess a signal supplied from the solid-state imaging apparatus 1001.The DSP circuit 1002 outputs image data obtained by processing thesignal from the solid-state imaging apparatus 1001. The frame memory1003 temporarily holds the image data processed by the DSP circuit 1002in units of frame.

The display part 1004 is configured of, for example, a panel-typedisplay apparatus such as liquid crystal panel or organic electroluminescence (EL) panel, and displays a moving picture or still imageshot by the solid-state imaging apparatus 1001. The recording part 1005records image data on a moving picture or still image shot by thesolid-state imaging apparatus 1001 in a recording medium such assemiconductor memory or hard disc.

The operation part 1006 outputs operation commands for various functionsof the electronic apparatus 1000 in response to user's operations. Thepower supply part 1007 supplies power to various power supplies asoperation power supplies of the DSP circuit 1002, the frame memory 1003,the display part 1004, the recording part 1005, and the operation part1006 as needed.

The electronic apparatus 1000 is configured as described above. <10.Exemplary Use of Solid-State Imaging Apparatus>

FIG. 34 is a diagram, illustrating exemplary use of the CMOS imagesensor 10 as an image sensor.

The CMOS image sensor 10 (FIG. 1) can be used in various cases forsensing lights such as visible light, infrared ray, ultraviolet ray, andX ray as described below, for example. That is, as illustrated in FIG.34, the CMOS image sensor 10 can be used not only in the field ofshooting images to be viewed but also in the field of traffics, in thefield of home electronics, in the field, of medical care and healthcare,in the field of security, in the field of beauty care, in the field ofsports, in the field of agriculture, or the like, for example.

Specifically, as described above, the CMOS image sensor can be used inapparatuses (such as the electronic apparatus 1000 of FIG. 33)configured to shoot an image to be viewed, such as digital camera,Smartphone, or camera-equipped cell phone, for example, in the field ofviewing.

The CMOS image sensor 10 can be used in apparatuses for traffics such asvehicle-mounted sensor configured to shoot in front of, behind, around,inside, and the like of an automobile, monitoring camera configured tomonitor a traveling vehicle or a road, or distance measurement sensorconfigured to measure an inter-vehicle distance or the like in order toachieve safe driving such as automatic stop or to recognize a driver'sstate or the like, for example, in the field of traffics.

The CMOS image sensor 10 can be used in apparatuses for home electronicssuch as TV receiver, refrigerator, and air conditioner in order to shoota user's gesture and to operate a device according to the gesture, forexample, in the field of home electronics. Further, the CMOS imagesensor 10 can be used in apparatuses for medical care or healthcare suchas endoscope, or angiographic apparatus using received infrared ray, forexample, in the field of medical care/healthcare.

The CMOS image sensor 10 can be used in apparatuses for security such asmonitoring camera for crime prevention or camera for personauthentication, for example, in the field of security. Further, the CMOSimage sensor 10 can be used in apparatuses for beauty care such as skinmeasurement device configured to shoot the skin or microscope configuredto shoot the scalp, for example, in the field of beauty care.

The CMOS image sensor 10 can be used in apparatuses for sports such asaction camera or wearable camera for sports or the like, for example, inthe field of sports. Further, the CMOS image sensor 10 can be used inapparatuses for agriculture such as camera configured to monitor thestates of field or crops, for example, in the field of agriculture.

Additionally, embodiments of the present technology are not limited tothe above embodiments, and may be variously changed without departingfrom the spirit of the present technology.

Further, the present technology can take the following configurations.

(1)

A solid-state imaging apparatus including:

a pixel array part in which pixels each having a first photoelectricconversion region formed above a semiconductor layer and a secondphotoelectric conversion region formed in the semiconductor layer aretwo-dimensionally arranged,

in which each of the pixels further has:

a first filter configured to transmit a light in a predeterminedwavelength region corresponding to a color component; and

a second filter having different transmission characteristics from thefirst filter,

one photoelectric conversion region out of the first photoelectricconversion region and the second photoelectric conversion regionphotoelectrically converts a light in a visible light region and theother photoelectric conversion region photoelectrically converts a lightin an infrared region,

the first filter is formed above the first photoelectric conversionregion, and

the second filter has transmission characteristics of making wavelengthsof lights in an infrared region absorbed in the other photoelectricconversion region formed below the first filter the same.

(2)

The solid-state imaging apparatus according to (1),

in which the first filter is a color filter.

(3)

The solid-state imaging apparatus according to (2),

in which the first photoelectric conversion region is a photoelectricconversion region configured to absorb and photoelectrically convert alight in a visible light region, and

the second photoelectric conversion region is a photoelectric conversionregion configured to photoelectrically convert a light in an infraredregion.

(4)

The solid-state imaging apparatus according to (3),

in which the second filter is formed above the first filter, and

has characteristics of transmitting through at least two wavelengthregions including a wavelength region of lights in a visible lightregion and a wavelength region of lights in an infrared region.

(5)

The solid-state imaging apparatus according to (3),

in which the second filter is formed between the first photoelectricconversion region and the second photoelectric conversion region, and

has characteristics of transmitting through a wavelength region oflights at least in an infrared region.

(6)

The solid-state imaging apparatus according to (5),

in which the second filter includes an inorganic film.

(7)

The solid-state imaging apparatus according to (5) or (6),

in which the second filter is a multilayered filter formed by laminatinga plurality of material with different refractive indexes,

(8)

The solid-state imaging apparatus according to (5),

in which the second filter is a metal thin-film filter in which apredetermined microstructural pattern is formed for a metal thin-film.

(9)

The solid-state imaging apparatus according to (2),

in which the first photoelectric conversion region is a photoelectricconversion region configured to absorb and photoelectrically convert alight in an infrared region, and

the second photoelectric conversion region is a photoelectric conversionregion configured to photoelectrically convert a light in a visiblelight region.

(10)

The solid-state imaging apparatus according to (9),

in which the second filter is formed above the first filter, and

has characteristics of transmitting through at least two wavelengthregions including a wavelength region of lights in a visible lightregion and a wavelength region of lights in an infrared region.

The solid-state imaging apparatus according to (9),

in which the second filter is a multilayered filter formed by laminatinga plurality of materials with different refractive indexes, and

has characteristics of transmitting through a wavelength region oflights at least in an infrared region.

(12)

The solid-state imaging apparatus according to any of (1) to (11),

in which each of the pixels has:

a first pixel circuit configured of:

-   -   a first charge/voltage conversion part configured to convert a        charge photoelectrically converted in the first photoelectric        conversion region into a voltage signal;    -   a first reset transistor configured to reset the first        charge/voltage conversion part;    -   a first amplification transistor configured to amplify the        voltage signal from the first charge/voltage conversion part;        and    -   a first select transistor configured to select and output the        signal voltage amplified in the first amplification transistor;        and

a second pixel circuit, configured of:

-   -   a second charge/voltage conversion part configured to convert a        charge photoelectrically converted in the second photoelectric        conversion region into a voltage signal;    -   a transfer transistor configured to transfer the charge from the        second photoelectric conversion region to the second        charge/voltage conversion part;    -   a second reset transistor configured to reset the second        charge/voltage conversion part;    -   a second amplification transistor configured to amplify the        voltage signal from the second charge/voltage conversion part;        and    -   a second select transistor configured to select and output the        signal voltage amplified in the second amplification transistor,        and

a feedback amplifier configured to feed back a readout signal from thefirst pixel circuit to a reset signal of the first reset transistor isprovided for the first pixel circuit.

(13)

An electronic apparatus mounting a solid-state imaging apparatusthereon, the solid-state imaging apparatus including:

a pixel array part in which pixels each having a first photoelectricconversion region formed above a semiconductor layer and a secondphotoelectric conversion region formed in the semiconductor layer aretwo-dimensionally arranged,

in which each of the pixels further has:

a first filter configured to transmit a light in a predeterminedwavelength region corresponding to a color component; and

a second filter having different transmission characteristics from thefirst filter,

one photoelectric conversion region out of the first photoelectricconversion region and the second photoelectric conversion regionphotoelectrically converts a light in a visible light region, and theother photoelectric conversion region photoelectrically converts a lightin an infrared region,

the first filter is formed above the first photoelectric conversionregion, and

the second filter has transmission characteristics of making wavelengthsof lights in an infrared region absorbed in the other photoelectricconversion region formed below the first filter the same.

REFERENCE SIGNS LIST

-   10 CMOS image sensor-   11 Pixel array part-   12 Vertical drive circuit-   13 Column processing circuit-   14 Horizontal drive circuit-   15 Output circuit-   16 Control circuit-   17 I/O terminal-   100 Pixel-   111-1 R color filter-   111-2 G color filter-   111-3 B color filter-   112 Organic photoelectric conversion layer-   115-1, 115-2, 115-3 Photodiode-   141 Dual-bandpass filter-   171 FD part-   172 Reset transistor-   173 Amplification transistor-   174 Select transistor-   175 Feedback amplifier-   181 Transfer transistor-   182 FD part-   183 Reset transistor-   184 Amplification transistor-   185 Select transistor-   200 Pixel-   211-1 R color filter-   211-2 G color filter-   211-3 B color filter-   212 Organic photoelectric conversion layer-   215-1, 215-2, 215-3 Photodiode-   241 Multilayered filter-   300 Pixel-   311-1 R color filter-   311-2 G color filter-   311-3 B color filter-   312 Organic photoelectric conversion layer-   315-1, 315-2, 315-3 Photodiode-   341 Plasmon filter-   400 Pixel-   411-1 R color filter-   411-2 G color filter-   411-3 B color filter-   412 Organic photoelectric conversion layer-   415-1, 415-2, 415-3 Photodiode-   441 Dual-bandpass filter-   500 Pixel-   511-1 R color filter-   511-2 G color filter-   511-3 B color filter-   512 Organic photoelectric conversion layer-   515-1, 515-2, 515-3 Photodiode-   541 Multilayered filter-   1000 Electronic apparatus-   1001 Solid-state imaging apparatus

What is claimed is:
 1. A solid-state imaging apparatus comprising: apixel array part in which pixels each having a first photoelectricconversion region formed above a semiconductor layer and a secondphotoelectric conversion region formed in the semiconductor layer aretwo-dimensionally arranged, wherein each of the pixels further has: afirst filter configured to transmit a light in a predeterminedwavelength region corresponding to a color component; and a secondfilter having different transmission characteristics from the firstfilter, one photoelectric conversion region out of the firstphotoelectric conversion region and the second photoelectric conversionregion photoelectrically converts a light in a visible light region andanother photoelectric conversion region photoelectrically converts alight in an infrared region, the first filter is formed above the firstphotoelectric conversion region, and the second filter has transmissioncharacteristics of making wavelengths of lights in an infrared regionabsorbed in the other photoelectric conversion region formed below thefirst filter same.
 2. The solid-state imaging apparatus according toclaim 1, wherein the first filter is a color filter.
 3. The solid-stateimaging apparatus according to claim 2, wherein the first photoelectricconversion region is a photoelectric conversion region configured toabsorb and photoelectrically convert a light in a visible light region,and the second photoelectric conversion region is a photoelectricconversion region configured to photoelectrically convert a light in aninfrared region.
 4. The solid-state imaging apparatus according to claim3, wherein the second filter is formed above the first filter, and hascharacteristics of transmitting through at least two wavelength regionsincluding a wavelength region of lights in a visible light region and awavelength region of lights in an infrared region.
 5. The solid-stateimaging apparatus according to claim 3, wherein the second filter isformed between the first photoelectric conversion region and the secondphotoelectric conversion region, and has characteristics of transmittingthrough a wavelength region of lights at least in an infrared region. 6.The solid-state imaging apparatus according to claim 5, wherein thesecond filter includes an inorganic film.
 7. The solid-state imagingapparatus according to claim 6, wherein the second filter is amultilayered filter formed by laminating a plurality of materials withdifferent refractive indexes.
 8. The solid-state imaging apparatusaccording to claim 5, wherein the second filter is a metal thin-filmfilter in which a predetermined microstructural pattern is formed for ametal thin-film.
 9. The solid-state imaging apparatus according to claim2, wherein the first photoelectric conversion region is a photoelectricconversion region configured to absorb and photoelectrically convert alight in an infrared region, and the second photoelectric conversionregion is a photoelectric conversion region configured tophotoelectrically convert a light in a visible light region.
 10. Thesolid-state imaging apparatus according to claim 9, wherein the secondfilter is formed above the first filter, and has characteristics oftransmitting through at least two wavelength regions including awavelength region of lights in a visible light region and a wavelengthregion of lights in an infrared region.
 11. The solid-state imagingapparatus according to claim 9, wherein the second filter is amultilayered filter formed by laminating a plurality of materials withdifferent refractive indexes, and has characteristics of transmittingthrough a wavelength region of lights at least in an infrared region.12. The solid-state imaging apparatus according to claim 1, wherein eachof the pixels has: a first pixel circuit configured of: a firstcharge/voltage conversion part configured to convert a chargephotoelectrically converted in the first photoelectric conversion regioninto a voltage signal; a first reset transistor configured to reset thefirst charge/voltage conversion part; a first amplification transistorconfigured to amplify the voltage signal from the first charge/voltageconversion part; and a first select transistor configured to select andoutput the signal voltage amplified in the first amplificationtransistor; and a second pixel circuit configured of: a secondcharge/voltage conversion part configured to convert a chargephotoelectrically converted in the second photoelectric conversionregion into a voltage signal; a transfer transistor configured totransfer the charge from the second photoelectric conversion region tothe second charge/voltage conversion part; a second reset transistorconfigured to reset the second charge/voltage conversion part; a secondamplification transistor configured to amplify the voltage signal fromthe second charge/voltage conversion part; and a second selecttransistor configured to select and output the signal voltage amplifiedin the second amplification transistor, and a feedback amplifierconfigured to feed back a readout signal from the first pixel circuit toa reset signal of the first reset transistor is provided for the firstpixel circuit.
 13. An electronic apparatus mounting a solid-stateimaging apparatus thereon, the solid-state imaging apparatus comprising:a pixel array part in which pixels each having a first photoelectricconversion region formed above a semiconductor layer and a secondphotoelectric conversion region formed in the semiconductor layer aretwo-dimensionally arranged, wherein each of the pixels further has: afirst filter configured to transmit a light in a predeterminedwavelength region corresponding to a color component; and a secondfilter having different transmission characteristics from the firstfilter, one photoelectric conversion region out of the firstphotoelectric conversion region and the second photoelectric conversionregion photoelectrically converts a light in a visible light region, andanother photoelectric conversion region photoelectrically converts alight in an infrared region, the first filter is formed above the firstphotoelectric conversion region, and the second filter has transmissioncharacteristics of making wavelengths of lights in an infrared regionabsorbed in the other photoelectric conversion region formed below thefirst filter same.